The current winter is a big win for seasonal forecasts

Seasonal forecasts for this winter were markedly accurate, with mild weather in Northern Europe in December and January predicted already in October. Researchers in the S2S4E project are now working to find out how to improve the reliability of future outlooks.

Before the winter set in, the seasonal forecast models from the world’s six leading weather agencies all agreed that there was a high chance of milder conditions than normal in Northern Europe this winter.

The seasonal forecasts published the following two months were on the same path, and now that December and January are over, we see that the seasonal forecasts were right: this winter has so far been markedly warmer than normal in Northern Europe.

Lower than normal electricity demand

The unusually warm weather this winter could have resulted in substantial reductions in power demand in Europe, particularly in those countries that rely on electricity for heating, such as France and the Scandinavian countries.

“In France, temperatures in December and January averaged 3°C above the seasonal norm, indicating power demand was about 6 GW below normal,” says Hannah Bloomfield, a researcher at the University of Reading who is involved in S2S4E project.

“In Sweden, it was about 5°C warmer than normal, and this implies that power demand there would have been around 2 GW lower than average,” she says, adding that “similar results are seen in Norway and Finland.”

More wintry conditions ahead?

The seasonal forecast model simulations launched at the beginning of January predict that the weather in Northern Europe will remain warmer than normal until the end of April, explains Nathalie Schaller, a senior researcher at CICERO Center for International Climate Research, who is also involved in the S2S4E project.

“The latest medium-range weather forecast simulations show a similar picture, predicting an almost record positive NAO over the coming weeks, meaning Europe will see more of the same mild weather,” Schaller adds.

S2S4E is a project funded by the EU's research and innovation programme Horizon 2020, which is working to make long-term forecasts more reliable and useful.

Over the coming months, researchers involved in the S2S4E project will analyse why the weather models turned out to be so accurate in their predictions for this winter, because understanding the reasons why could help scientists improve the models.